Various types of metal joists or trusses for buildings wherein the overhead structure provides support for curtain suspension systems and other equipment are available commercially and known in the prior art. An increasing problem exists in the installation of stage equipment and curtain suspension assemblies--particularly the larger heavy-duty assemblages--in the labor costs of installing same. Thus, as the systems become more complicated, time required for installation and the level of skill required increases. It has occurred to the inventor that this problem may be solved through designing and manufacturing complete suspension systems including the overhead joists at the plant as relatively simplified units which can be installed without the necessity of complicated or involved construction procedures and which at the same time are adaptable to a wide variety of architectural arrangements which may be encountered particularly in commercial and public establishments.